Leroy, New York Weather Forecast Discussion

045
FXUS61 KBUF 271036
AFDBUF
Area Forecast Discussion
National Weather Service Buffalo NY
636 AM EDT Sat Sep 27 2025
.SYNOPSIS...
High pressure building east and then south across the Great Lakes
will lead to an extended period of dry weather through the weekend
and all of next week. Warm daytime temperatures through Tuesday will
cool to more seasonable levels by Wednesday, then trend back above
normal later in the week.
&&
.NEAR TERM /THROUGH TONIGHT/...
Calm, clear conditions overnight has allowed for typical valley fog
to develop in the S. Tier with patchy radiation fog elsewhere. The
radiation fog will be the first to dissipate shortly after sunrise,
with the valley fog receding within a few hours afterward.
Through the period the forecast area will become sandwiched between
a trough drifting east towards the Southeast coast, a stout ridge
building across the Mississippi Valley to the Great Lakes, and
another flattening trough moving east into ON/QC. The high pressure
ridge will be the dominant feature in terms of impacts on regional
sensible weather. There may be some added low clouds from a washed
out frontal boundary draped across Lake Ontario, or high clouds
streaming north from the coastal trough, but dry conditions will
persist through tonight with another round of valley fog likely in
the S. Tier.
Temperatures will be noticeably warmer than yesterday, topping out
in the mid/upper 70s to around 80 in most areas this afternoon, with
a range of 50s to near 60s for lows tonight.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
Fantastic summer-like weather is on tap with dry weather and well
above normal temperatures. Highs will peak well into the 70s to low
to mid 80s Sunday through Tuesday. Light winds and clear skies will
`likely support some fog in the river valleys given the longer
nights.
A moisture starved cold front will drop south through the region
Tuesday night. All indications are we will see a cooler air mass
arrive across the eastern Great Lakes with temps returning back to
near normal for the rest of the week.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
Impressive sfc ridge builds in from the north Wednesday behind the
moisture starved cold front. CAA behind this front will send H850T`s
back into the single digits above zero. We should shave a solid 12F
to 15F off temps Wednesday with highs found mainly in the 60s. Given
the cooler airmass the main concern in this period will be `frost`
potential Wednesday night, and to a lesser degree Thursday night.
The limiting factor for Wednesday night may be wind flow given the
sfc high will not be directly overhead. For Thursday night...the
airmass begins to modify as WAA processes begin to take over but
will `not` completely eradicate this potential.
Otherwise...the cooler airmass will make for phenomenal sleeping
conditions, and then fantastic afternoon fall-like weather as we
head towards the weekend.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
Variable flight conditions across the region through about 13z. A
washed out frontal boundary will produce MVFR cigs mainly east of
Lake Ontario (KART/GTB). Further south, IFR or lower valley fog is
found across the Southern Tier with patchy radiation fog and stratus
elsewhere. IFR vsbys cannot be ruled out at any one location though
aside from KJHW, KIAG looks to be most likely TAF site south of Lake
Ontario to see impacts to cigs/vsbys through daybreak.
Once fog dissipates later this morning, VFR will prevail areawide
with lingering mid level clouds from the front and high clouds from
a low pressure system over the Mid-Atlantic moving into the region.
Another round of valley fog is expected in the Southern Tier
tonight, though radiation fog outside this area should be limited
with slightly more gradient wind in place.
Outlook...
Sunday through Wednesday...Mainly VFR. Valley fog and local IFR
possible each late night through morning.
&&
.MARINE...
High pressure will slowly build east across the Great Lakes through
the weekend, becoming centered directly overhead early Monday
morning. The high will remain in close proximity through much of the
week, though strengthen and shift east of the lakes later in the
week. Overall this pattern this will keep the area rain free with
winds and waves below SCA criteria through at least Tuesday, though
occasional weak frontal passages may cause 10-15kt onshore flow with
a small chop on the nearshore waters at times.
A stronger push of cooler air into the region will cause northeast
winds to sharply increase Tuesday night into Wednesday night with a
period of SCA conditions expected, especially on Lake Ontario.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...None.
&&
$$
SYNOPSIS...PP
NEAR TERM...PP
SHORT TERM...AR
LONG TERM...AR
AVIATION...PP
MARINE...PP

NWS BUF Office Area Forecast Discussion